/* Dossier technique : une colonne, section « chemin de l'eau » en scrollytelling (coupe sticky + étapes) */
:root{
  --bg:#f3f5f6; --band:#e9eef1; --panel:#ffffff; --ink:#15202b; --muted:#56636f; --line:#d5dbe0;
  --water:#1d6fd6; --water-soft:rgba(29,111,214,.14); --trap:#c2410c; --trap-soft:rgba(194,65,12,.12);
  --bitumen:#2a2f35; --pir:#cfe1f2; --pir2:#b9d3ec; --wood:#d9b27c; --wood2:#c69a5f; --gravel:#b7b2aa; --steel:#9aa6b1; --resopal:#4a5560; --vb:#b4232a;
  --bar:#6f97c4; --bar-hot:#1d6fd6;
  --f-display:"Archivo","Helvetica Neue",Arial,sans-serif;
  --f-body:"IBM Plex Sans","Helvetica Neue",Arial,sans-serif;
  --f-mono:"IBM Plex Mono",ui-monospace,Menlo,monospace;
}
@media (prefers-color-scheme:dark){:root{
  --bg:#0f151b; --band:#131b22; --panel:#18212a; --ink:#e6ebf0; --muted:#9aa7b3; --line:#2a3540;
  --water:#5aa2ff; --water-soft:rgba(90,162,255,.16); --trap:#fb8a4c; --trap-soft:rgba(251,138,76,.14);
  --bitumen:#05070a; --pir:#2d4863; --pir2:#35577a; --wood:#9a7646; --wood2:#86653a; --gravel:#6d6a64; --steel:#6d7a86; --resopal:#8c99a5; --vb:#ef5a61;
  --bar:#4f79a8; --bar-hot:#5aa2ff; color-scheme:dark}}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:17px;line-height:1.6;-webkit-font-smoothing:antialiased}
.wrap{max-width:1120px;margin:0 auto;padding-inline:20px}
h1,h2,h3{font-family:var(--f-display);margin:0;line-height:1.12;text-wrap:balance}
h2{font-size:clamp(24px,3.2vw,32px);font-weight:700}
h3{font-size:18px;font-weight:700}
p{margin:0}
.eyebrow{font-family:var(--f-mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin-bottom:10px}
.muted{color:var(--muted)} .small{font-size:14px}
.mono{font-family:var(--f-mono);font-variant-numeric:tabular-nums}
section{padding-block:88px}
.band{background:var(--band)}
.section-title{margin-bottom:14px}
.intro{max-width:66ch;margin-bottom:28px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:8px;padding:20px;min-width:0}
.two{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:20px}
.prose{display:flex;flex-direction:column;gap:12px;font-size:16px}

/* hero */
.hero{padding-block:72px 64px;border-bottom:1px solid var(--line)}
.hero-title{font-size:clamp(34px,6vw,68px);font-weight:800;letter-spacing:-.015em;margin-block:8px 26px}
.hero-title .line{display:block}
.hero-title .accent{color:var(--water)}
.lead{font-size:19px;max-width:62ch;margin-bottom:36px}
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px}
.stat{background:var(--panel);border:1px solid var(--line);border-radius:6px;padding:16px 18px;display:flex;flex-direction:column;gap:6px;min-width:0}
.stat b{font-family:var(--f-display);font-size:34px;font-weight:800;font-variant-numeric:tabular-nums;line-height:1}
.stat.alert b{color:var(--trap)}
.stat>span{font-size:14px;color:var(--muted);line-height:1.45}
.scrollcue{display:inline-flex;gap:8px;margin-top:34px;color:var(--ink);font-weight:500;text-decoration:none;border-bottom:2px solid var(--water);padding-bottom:2px}
.scrollcue:focus-visible{outline:2px solid var(--water);outline-offset:4px}

/* scrollytelling */
.scrolly{padding-block:40px}
.scrolly-grid{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(0,1fr);gap:40px;align-items:start}
.scrolly-graphic{position:sticky;top:max(16px,calc(50vh - 260px));}
.graphic-card{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:18px}
.graphic-card svg{display:block;width:100%;height:auto}
.progress{display:flex;gap:6px;margin-top:10px}
.progress span{flex:1;height:3px;border-radius:2px;background:var(--line);transition:background .3s}
.progress span.on{background:var(--water)}
.progress span.on.trap{background:var(--trap)}
.scrolly-steps{display:flex;flex-direction:column;padding-block:12vh 30vh}
.step{min-height:70vh;display:flex;flex-direction:column;justify-content:center;gap:12px;opacity:.28;transition:opacity .4s}
.step.is-active{opacity:1}
.step h2{font-size:clamp(22px,2.6vw,28px)}
@media (max-width:860px){
  .scrolly-grid{grid-template-columns:1fr;gap:0}
  .scrolly-graphic{top:8px;z-index:2}
  .graphic-card{padding:10px}
  .scrolly-steps{padding-block:4vh 20vh}
  .step{min-height:60vh;background:var(--bg);padding:14px 0}
}
.lbl{font:12px var(--f-mono);fill:var(--muted)}
.lbl-ink{font:500 12px var(--f-mono);fill:var(--ink)}
.lbl-ink.water{fill:var(--water)} .lbl-ink.trap{fill:var(--trap)}
.hl{stroke:var(--trap);stroke-width:2.5;fill:none;stroke-dasharray:5 4}
.stage{opacity:0}

/* couches */
.stack-grid{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr);gap:28px;align-items:start}
@media (max-width:760px){.stack-grid{grid-template-columns:1fr}}
.stack{display:flex;flex-direction:column;gap:6px;perspective:900px}
.slab{all:unset;box-sizing:border-box;display:grid;grid-template-columns:1fr auto;gap:12px;align-items:center;cursor:pointer;border-radius:4px;padding:10px 14px;color:var(--ink);font-size:15px;border:1px solid var(--line);background:var(--panel);position:relative;overflow:hidden}
.slab::before{content:"";position:absolute;inset:0 auto 0 0;width:10px;background:var(--c)}
.slab .nm{padding-left:10px}
.slab .th{font:12px var(--f-mono);color:var(--muted)}
.slab[aria-pressed="true"]{border-color:var(--ink);box-shadow:0 0 0 1px var(--ink)}
.slab:focus-visible{outline:2px solid var(--water);outline-offset:2px}
.slab.block{border-left-width:1px}
.slab .badge{position:absolute;right:10px;top:-9px}
.zone-trap{border:2px dashed var(--trap);border-radius:6px;padding:6px;display:flex;flex-direction:column;gap:6px;position:relative;background:var(--trap-soft)}
.zone-trap .zlabel{font:500 12px var(--f-mono);color:var(--trap);padding:2px 4px}
.layerinfo{background:var(--panel);border:1px solid var(--line);border-radius:8px;padding:20px;display:flex;flex-direction:column;gap:10px;position:sticky;top:20px}
.tag{display:inline-block;font:500 12px var(--f-mono);padding:2px 9px;border-radius:999px;border:1px solid currentColor}
.tag.block{color:var(--trap)} .tag.open{color:var(--water)}

/* calcul */
.calc{display:flex;flex-direction:column;gap:12px}
.calc label{display:flex;justify-content:space-between;gap:12px;font-size:15px}
.calc input[type=range]{width:100%;accent-color:var(--water)}
.calc-out{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:6px;font-size:14px}
.result{font-family:var(--f-display);font-size:40px;font-weight:800;color:var(--trap);font-variant-numeric:tabular-nums;line-height:1.1}
.hourglass{height:10px;border-radius:5px;background:var(--bg);overflow:hidden}
.sand{height:100%;width:0;background:linear-gradient(90deg,var(--water),var(--trap))}

/* constats */
.photo{display:grid;grid-template-columns:minmax(0,300px) minmax(0,1fr);gap:24px;align-items:start;margin-bottom:28px}
.photo img{width:100%;height:auto;border-radius:6px;border:1px solid var(--line)}
.photo div{display:flex;flex-direction:column;gap:10px}
@media (max-width:640px){.photo{grid-template-columns:1fr}}
.timeline{list-style:none;margin:0;padding:0;position:relative}
.timeline::before{content:"";position:absolute;left:150px;top:6px;bottom:6px;width:2px;background:var(--line)}
.timeline li{display:grid;grid-template-columns:150px 1fr;gap:28px;padding:12px 0;position:relative}
.timeline li::after{content:"";position:absolute;left:145px;top:21px;width:12px;height:12px;border-radius:50%;background:var(--panel);border:2px solid var(--muted)}
.timeline li.key::after{background:var(--trap);border-color:var(--trap)}
.timeline time{font-family:var(--f-mono);font-size:13px;color:var(--muted);padding-top:3px;font-variant-numeric:tabular-nums;text-align:right;padding-right:10px}
@media (max-width:560px){.timeline::before{left:5px}.timeline li{grid-template-columns:1fr;gap:2px;padding-left:24px}.timeline li::after{left:0}.timeline time{text-align:left}}

/* météo */
.chartbox{position:relative;overflow-x:auto}
.chartbox svg{display:block;width:100%;min-width:640px;height:auto}
.tip{position:absolute;pointer-events:none;background:var(--ink);color:var(--panel);font:13px var(--f-mono);padding:5px 8px;border-radius:4px;white-space:nowrap;transform:translate(-50%,-115%)}
.cmp{display:flex;flex-direction:column;gap:12px;margin-block:24px 18px}
.cmprow{display:grid;grid-template-columns:230px 1fr 90px;gap:12px;align-items:center;font-size:15px}
.track{height:14px;background:var(--bg);border-radius:3px;overflow:hidden}
.fill{height:100%;width:0;border-radius:0 4px 4px 0}
.fill.hot{background:var(--bar-hot)} .fill.ref{background:var(--muted)}
@media (max-width:560px){.cmprow{grid-template-columns:1fr 70px}.cmprow .track{grid-column:1/-1;grid-row:2}}
details summary{cursor:pointer;font-weight:500}
.tables{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:20px;margin-top:14px;overflow-x:auto}
table{border-collapse:collapse;font-size:14px;width:100%}
th,td{padding:6px 10px;border-bottom:1px solid var(--line);text-align:left}
.n{text-align:right;font-family:var(--f-mono);font-variant-numeric:tabular-nums}

/* évacuations */
.areas{display:flex;align-items:flex-end;gap:6px;height:140px;margin-block:10px 28px;max-width:720px}
.area{border-radius:4px;display:flex;align-items:flex-end;padding:10px;font-size:14px;line-height:1.3;color:var(--ink);transform-origin:bottom}
.area.slope{flex:140;height:100%;background:var(--water-soft);border:1px solid var(--water)}
.area.flat{flex:55;height:100%;background:var(--trap-soft);border:1px solid var(--trap)}

/* demandes */
.asks{margin:0;padding-left:24px;display:flex;flex-direction:column;gap:10px;max-width:74ch}

footer{border-top:1px solid var(--line);padding-block:28px 48px;font-size:13px;color:var(--muted)}
footer .wrap{display:flex;flex-direction:column;gap:6px}

@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.step{opacity:1}}